Urban agriculture has gained increasing traction in both academic and professional discourse, yet the concept of the urban agriculture center has remained without a recognized definition or an established theoretical framework. The term appears across architectural design, policy documents, and professional sources without converging on a shared meaning, and no study has defined it through systematic international comparison or derived a transferable model for its composition or creation. This thesis addresses that gap. The research is organized around three questions: what an urban agriculture center is, how it is composed, and how it starts. These are pursued through a multiple-case study design suited to "how" and "what" questions about a relatively novel phenomenon.